Just 150 miles away from the Standing Rock Dakota Access Pipeline protest in North Dakota, another crude oil pipeline has leaked and contaminated Ash Coulee Creek with at least 176,000 gallons of oil. The pipeline in question, the Belle Fourche Pipeline, was found to be actively leaking near the city of Belfield on December 5 by a landowner.

Belfield is just two and a half hours from Cannon Ball, the central hub of the Standing Rock protest and the disputed area of the final piece of the Dakota Access pipeline.

The protest against the Dakota Access Pipeline, led by the Standing Rock Sioux Tribe, has been ongoing for months now and got its grassroots start because the Standing Rock Sioux argued that the path of the $3.8 billion pipeline threatens their clean water. As NBC News reports, the pipeline is slated to cross underneath Lake Oahe, which provides drinking water to thousands of Native Americans.

Energy Transfer Partners, the company behind the Dakota Access Pipeline, has repeatedly ensured that the controversial pipeline is safe, but events like this recent spill underscore the concerns of the Standing Rock Sioux Tribe and other so-called “water protesters,” many of whom have been living at the Standing Rock site for months to protest the pipeline.

Reportedly, the pipeline that burst just 150 miles from the Standing Rock epicenter was equipped with electronic monitoring equipment that should have detected the leak when it began – well before it reached 176,000 gallons – but that equipment somehow failed. According to Wendy Owen, who spoke on behalf of True Cos., the operator of the leaky crude oil pipeline, nobody yet knows why the electronic monitoring equipment didn’t do its job.

After the extensive pipeline leak near Standing Rock was discovered on December 5, the pipeline was immediately shut down according to True Cos. While an investigation into the leak is still ongoing, Owen says that the “sloughing” of the hill where the pipeline is buried could have caused damage that resulted in the leak that contaminated Ash Coulee Creek.

“That is our number one theory, but nothing is definitive. We have several working theories and the investigation is ongoing.”

The leaking oil pipeline just a stone’s throw from Standing Rock was discovered at around the same time that the U.S. Army Corps of Engineers announced that it was denying the necessary easement that would have allowed the Dakota Access Pipeline to be completed by routing under Lake Oahe.

While that announcement was celebrated as a huge victory for those protesting the pipeline at Standing rock, protesters who had just been joined by thousands of U.S. military veterans, the decision is far from the end of the Standing Rock battle. Immediately following the Army Corps of Engineers’ announcement, which advised Energy Transfer Partners to find a different route for their multi-billion dollar pipeline, the parent company behind the controversial DAPL said they intended to keep building as planned.

Energy Transfer Partners has attempted to placate the Standing Rock protesters by assuring them that the Dakota Access Pipeline will include leak detection equipment (similar to the failed equipment involved in the 176,000-gallon Belle Fourche Pipeline spill) and remote monitors with the capability to quickly “shut down” portions of the DAPL in the event that a spill was detected.

Standing Rock protesters have, thus far, indicated that leak detection equipment and remote monitors don’t assuage their concerns, and are still camped out by the thousands only 150 miles from where the Ash Coulee Creek contamination was discovered on December 5.

The fate of the Dakota Access Pipeline is still up in the air. Standing Rock protesters have vowed to stand their ground, even against the wishes of Standing Rock Sioux tribal elders and throughout the harsh North Dakota winter. The U.S. Army Corps of Engineers has declined the necessary easement to continue construction on the current route. However, Donald Trump has expressed support for the project and things could change in the weeks and months to come.

Reportedly, the Belle Fourche Pipeline spill has done significant damage to both private and public lands along Ash Coulee Creek, stretching almost six miles from the source of the leak. Since the time of the spill, the creek has frozen over, trapping crude oil under the ice.

Dozens of employees are diligently working to mitigate the damages of the December pipeline spill and clean up the 176,000 gallons of oil that burst from the pipeline. The work is slow-going given the magnitude of the spill and the weather. So far, only approximately 37,000 gallons of the oil has been recovered and removed from the environment so close to the disputed Standing Rock site, planned future home of the Dakota Access Pipeline.